Automatic chuck



Jan. 26 1926.

v 1,570,724 F. BECK AUTOMATIC CHUCK Filed Nov. 9, 1921 4 Sheets-She et '1 Fig.1

ma W Adv-ply Jan. 26 1926. 1,570,724

F. BECK AUTOMATI C CHUCK Filed Nov. 9, 1921 4 Sheets-Sheet 2 Fig. 2

Jan. 26 1 926.

F. BECK AUTOMATIC CHUCK 1 Filed NOV. 9, 1921 4 Sheets-Sheet 3 Jan. 26 1926. 1,570,724

' F. BECK AUTOMATIC CHUCK Filed Nov. 9, 1921 4 Sheets-Sheet 4.

Fig; 4:

Patented Jan. 26, 1926.

FRE ERIQ BE K, E N-EUILLY-son-sEINE, FRANCE.

AUTOMATIC/CHUCK Application filed November 9, 1921. Serial No. 514,025.

To all whom'it may concern Be it known *that "1,"FREDERICL BECK, a

citizen of the French Republic, V-resid-ing at Neuilly-sur-Seine, Seine,- France, 46 Rue '6 Ibry; hEtVBlllVGlltGdTIlGW and; useful "Imtion.

=This invention relates to 'an automatic chuck intended -toho1d 'a- Working-tool or any material to be worked 'uponin a lathe i or similar machine, and in which the clampinggear causes equal and-simultaneous radial movements of. the clampingdogs.

I This movement, which has been realized in other; devices of .thesame xkind, is-obtained, in thechuok according to this invention, by means of mechanical arrangements, in which are used certain elements, known in theart,-but which are combined with-each other so as to-insure an automatic-centering of the object 11 clamped relatively o to. the axis of the-chuck, together with the tightening thereof.

Said-chuck is: simpler inconstructionthan the analogous devices heretofore inuse', owing to the fact that its elements are 'easily manufactured -even with very I restricted manufacturing facilities.

Two practical embodiments oftheinvention are illustrated, by way ofexamplearin the accompanying diagrammatic drawings, in "which I Fig. 1 is, a ,rear'elevation, with partsremoved; i

Fig.- Q-Iis alongitudinal-section -on line Fig.3 is a-tra'nsverse-section{on "line II of Fig. 4; H Fig; 4 is a longitudinalsection online II-Il ot'Fig. 3;, 8

Figs. 5,, 6, 7, 8 and 9-show respectively, a

side elevation, aplan viewfrom above, a

plan View 'frombelow, a lateral elevation and a transversal section on line VIIVII (Figure 5) wof'one of the axes of the toothed pinions actuating the clamping 'dogs.

"10 is a-sectional view L'showing'the.

pinion -mounting. p

In the" structural fornraccordin'g to Figures 1 and 2, a :discl, fastened, inthe usual manner, upon thespindle 2 of the machine, is provided withradial: grooves 3, in which can slide clamping dogs l.- Said grooves and-dogs compriseanysuitableguiding-de vice allowing only movements of rectilinear translation of each dog alongits groove. The movement of each 'ofthe-dogs, isobtained 'by-meansof a toothedpinion- 5 act- I ing upon the teethfiof the-rack; Gfforniing part'of the inner iiace of the adjacentdogl, The actuation of the rack-by the pinion takes place througlran aperture '7 provided in the disc 1.

his arrangement enables the samedogs to be used-whatever bethe di-rection'o'ftheir action '-(inwardly or outwardly), for it is sufliclent "to reverse them end for rend in order that their steps be properly turned-in view of' their desired action.

" Thetoothed' pinions are in turn,- putinto motion-by means of a sc-rew element- 8 rot-atingaround the axis of the chuck-=and meshing with said #pinions.

As the pinions 5, corresponding-to the dogs: 4,: all intermeslr simultaneously with the svrew-elementffi, to each movement otthe latter :Will correspond simultaneous and equal movementsiof the dogsi, whatever be the number 0f said dogs and their relative angular positions around the disc 1.

The screwelement 8 is formed upon a part 9- which rotates concentrically with the axis of the chuck around the sleeve 10 o'f the disc 1. This sleeve 10-may be integral with or separate from "said disc, provided thatit he 1 secureditheretogin a rigid manner. 7 a

' -The part 9 which rotates around the 51 eve 10must notbe capable iofxlongitudinal movemenu onl' the axisotrotation. Tol -prevent longitudinal: movements and to takeup :any longitudinal-play any suitable imeansimay be; em ployed, for instance, asgshown in Figure 2,-where a tightening nut "11 is=em ployed. v l I 'Thetoothed pinions 5 rotate around. axles 12 which-are rigidly connected with the .disc 1. This connection may be realized-in any suitable manner, suchas, for instance, shown in Figure 2 (in 1 order to enable an easy -d-ismantling- 0f l the Whole) by :fastening them into an auxiliary circular part v 21 3, which is itself rigidly connected wit-lrthe disc 1.

lRotationaround its axis may be given to thepartfi) bearing the screw element 8 :in' any manner suited to the particular conditions of-useof the chuck.

- Said rotation may -:be- =realized,:.:for instance, as shown in Figures 1 and 2, by the action of a small toothed pinion 1a (the axis of which is supported by the auxiliary part 13 and by the rear disc 15 covering the mechanism of the chuck) upon a toothed crown 16 integral with or rigidly connected to the part 9.

The pinion 14: may be rotated by means of a spanner acting upon the squared end of the pinion.

The actuation might also be obtained by means of a greater number of pinions 14- acting upon a. single toothed crown 16, assuming that their simultaneous action be controlled by any suitable device.

In the example of construction of the chuck illustrated by Figures 1 and 2, the divided pitch 7? of the multiple thread screw element 8 is equal to the pitch or" the pinion 5 and, consequently, to that of the rack 6.

According to this invention, to facilitate the assemblage of the chuck, the screw 8, the pinions 5, and the racks 6 are so chosen as to make the dogs 4 mutually interchangeable as well as reversible end for end. To accomplish this, screw 8 is furnished with a multiple thread, the true pitch of which is equal to the pitch of the pinions 5 times an integer which is equal to, or a multiple of, the number of pinions used; while the number 01"" threads on the multiple screw 8 is equal to said integer.

For example, in the case illustrated, the number of pinions 5, is three, and thus the screw 8 has a triple thread, the divided pitch of which is equal to the pitch of the pinions 5, and the true pitch of which is three times the pitch of pinions 5.

With this construction the relative positions of the pinions 5 remain unchanged during operation, and so permit the use of any dog 4, with any pinion 5.

Under such conditions, the dogs are interchangeable and the assemblage of the chuck becomes very simple and rapid since there is no need of ascertaining which of the racks intermeshes with each of the pinions.

Figures 3 to 9. illustrate an improved structural form of a chuck according to the invention, comprising two improvements the one of which enables the simplifying of the construction of the apparatus, and the other cut by a milling machine, when the chuck body has been previously turned in a lathe. Besides that the cost of the workmanship, is increased by this subsequent milling operation, and is pretty difficult, because it requires sufticient skill and special care in order that, all the grooves be located accurately at the same distance from the center.

Said milling operation may be dispensed with by substituting for these rectilinear grooves, arcuate grooves limited by two cylindrical surfaces, as shown in Fig. 3, the axes of which coincide with the axis of the chuck, which grooves may be cut in brackets 1 in plate 16, by the lathe tool itself working endwise between the two circumferences 2 and 3.

To the ends of each of the axes at of the pinions 5 for actuating the dogs 6 is given, in this case, an arcuate shape (Figures 5 to 9) identical with that of the grooves in which they are housed.

In other words, the axis 1 consists of a cylindrical mass of metal, steel for instance,

"from which are cut oil, with a file or a milling tool, all the parts comprised between the outline drawn in full lines and the rectangle shown in pick-and-dot lines on Figure 5, care being taken to accurately fit the ends of the axis l into the arcuate grooves in such a manner that they engage the said grooves without any play, wherein they are afterwards fastened by means of pins 7.

The second in'iprovement relates to a de vice intended to accelerate the clamping by enabling the dogs 6 to be moved simultaneously and very quickly towards or away from each other, by means of a square ended T-spanner, engaging the socket in a bevel pinion meshing with the toothed crown provided on the central screw element actuating the dogs through the medium of their pinions.

Said improvement consists in having cast with, or fastened to, a screw element 8" (Figure 4) a disc 9, the milled periphery 10 of which is provided externally with a rounded projecting flange 11 adapted to be easily grasped by the hand, and provided internally with a bevel toothed crown 12' meshing with a correspondingly beveled pinion 13 mounted loosely upon a spindle 14 supported by a bracket 15 integral with the disc 16'.

For quickly bringing the dogs 6 into contact with the material or the working tool to be clamped by the chuck, it suflices to rotate the disc 9 in order to move the screw element 8 in the proper direction, the rotation of which is transformed by the pinions 5 and the racks 17 into a simultaneous radial translation of the dogs 6. The final tightening, as intensive as it is desirable, is

given by rotating in the proper direction, by means of a square-ended T-spanner inserted into the socket 18, the conical pinion 13, and, consequently the disc 9 and the screw element 8.

The feature of interchangeability of the clamping dogs is provided for in this case in exactly the same manner as set forth above with regard to Figures 1 and2.

For loosening, the reverse operations are performed.

The above described improvements are equally applicable to chucks provided with four, or more, clamping dogs, which may be either ordinary dogs, or, as shown in Figures 3 and 4, dogs with adjustable jaws.

I now claim:

1. An automatic chuck comprising a plate, clamping dogs positioned on said plate, pinions for operating said dogs, means for operating said pinions, an annular groove in the plate, the pinions being carried by axes so shaped as to fit snugly into, and to completely fill the portions of the said annular groove occupied by the free ends of said.

axes.

2. An automatic chuck comprising a plate, clamping dogs associated with said plate, racks on the dogs, pinions for meshing with the racks formed on said dogs, said pinions being positioned in slots intersecting an annular channel in said plate and belng carried by axes so formed as to snugly fit into chuck, so that the relative position of the pinions remain unchanged during operation of the chuck, whereby to make the dogs mutually interchangeable. v

4. An automatic chuck, comprising, a plate, clamping dogs slidably positioned in the plate, pinions for operating the dogs, an endless screw for operating the pinions, said endless screw having a multiple thread equal in number to an integer equal to or a multiple of the number of pinions in the chuck, the divided pitch of which is equal to the pitch of the pinions and the true pitch of which is equal to the divided pitch times the said integer, so that the relative position of the pinions remain unchanged during operation of the chuck, whereby to make the dogs mutually interchangeable.

In testimony whereof I have signed this specification.

FREDERIC BECK. 

